A process for industrially producing a 2-position branched alcohol (such as 2-octyl-1-dodecanol) by applying so-called Guerbet reaction to a higher alcohol (such as 1-decanol) has been conventionally known. However, only one report has been made for a technique for producing a 2-position branched aldehyde (see Patent Document 1). According to Patent Document 1, in the case where a branched saturated aldehyde is produced by utilizing Guerbet reaction, a branched alcohol and a branched unsaturated aldehyde are present as mixtures, and thus it is expected that it is difficult to produce a branched saturated aldehyde with high purity. Patent Document 1 disclosed in Example 2 that the amount of a hydrogenation catalyst is necessarily added in an amount of 7% by mass for improving the yield of the branched aldehyde, but when the ratio of the hydrogenation catalyst is decreased, such a problem and the like arise in that a branched alcohol is produced as the major product.
An aldehyde with a 2-position branched long-chain alkyl can be produced through dimerization of a higher alcohol utilizing Guerbet reaction, but the production process is not practical since the activity per unit catalyst is significantly low.
Acid rearrangement reaction of a 1,2-epoxide of an α-olefin provides various rearrangement products (which include aldehydes, and also include ketones and unsaturated alcohols), and thus a 1,2-epoxide is utilized only for production of a 1,2-diol through hydration reaction or production of a polyester polyol through addition reaction with a dibasic carboxylic acid. It has been reported that acid rearrangement of a 1,2-epoxide in a 1,4-dioxane solvent provides a linear aldehyde (see, for example, Patent Document 2). However, an aldehyde with a 2-position branched long-chain alkyl cannot be produced by the production method using an epoxide of an α-olefin.
Patent Document 1: U.S. Pat. No. 3,558,716
Patent Document 2: JP-A-2004-256404